Context. Bisectors of strong, single spectral lines, usually the Fe  6252 line, have traditionally been used to examine the velocity fields in stellar atmospheres. This requires high S/N often achieved by summing many individual spectra. Aims. We investigate whether bisectors derived from cross-correlation functions (CCF) of single-exposure spectra can be used to provide information on stellar...

In this second part of a series of surveys on the geometry of finite dimensional Banach spaces (Minkowski spaces) we discuss results that refer to the following three topics: bodies of constant Minkowski width, generalized convexity notions that are important for Minkowski spaces, and bisectors as well as Voronoi diagrams in Minkowski spaces.

Most methods for computing offsets and bisectors of parametric curves are based on a local formulation of the distance to a curve. As a consequence, the computed objects may contain spurious parts and components, and have to be trimmed. We approach these problems as global optimization problems, and solve them using interval arithmetic, thus generating robust approximations that need not be tri...

Context. Spectral-line asymmetries (displayed as bisectors) and wavelength shifts are signatures of the hydrodynamics in solar and stellar atmospheres. Theory may precisely predict idealized lines, but accuracies in real observed spectra are limited by blends, few suitable lines, imprecise laboratory wavelengths, and instrumental imperfections. Aims. We extract bisectors and shifts until the ‘u...

This paper studies load balancing issues for classes of problems with certain bisection properties. A class of problems has -bisectors if every problem in the class can be subdivided into two subproblems whose weight (i.e. workload) is not smaller than an -fraction of the original problem. It is shown that the maximum weight of a subproblem produced by Algorithm HF, which partitions a given pro...